The SR-71 night time flight performance restrictions were lifted so the flight could be flown at max Mach (3.2) and turns made at max bank of 35 degrees instead of the normal 25-degrees.
The following story comes from former SR-71 Blackbird Reconnaissance Systems Officer (RSO) Colonel Richard Sheffield’s unpublished book.
As Linda Sheffield Miller, who is Colonel Sheffield’s daughter and who also runs the awesome Facebook Page Habubrats (CLICK HERE to check it out), explained to The Aviation Geek Club, what makes this post even more interesting is that it was written by Colonel Hal Confer, 9th Strategic Reconnaissance Wing (SRW) Commander 1970-1972, while he was recommending that Colonels Robert Spencer and Richard Sheffield got the Silver Star for their effort during a risky mission flown in the skies over Vladivostok. But, as Linda Sheffield Miller explained us, Confer couldn’t put the recommendation in because it was a highly classified sortie and only a few people knew about it.
Vladivostok, September 27, 1971, SR-71, #980
In 1971, Colonels Robert (Bob) Spencer and Richard (Butch) Sheffield flew one of the most important combat missions of the Cold War.
The Soviet Union had developed and deployed throughout the USSR a radar and missile system called the SA-5. It was designed to intercept and destroy overflying US bombers and fighters. The Soviet Union had gone to extreme measures to keep secret the parameters of the SA-5 radar frequencies.
The deployment of the SA-5 presented a considerable degradation to the US bomber forces ability to successfully strike the Soviet Union. Consequently, obtaining the SA-5 radar profile was one of the National intelligence community’s highest priorities.
The Soviets were very sensitive to any SR-71 flight activities on or near their borders; it was decided to use the SR-71 to bait the Soviets into exposing their SA-5 system. A special ELINT recorder was designed by NSA to be carried on the SR-71 to collect the SA-5 radar signal.
The mission tactics were to surprise the SA-5 missile site at the port city of Vladivostok. The SR-71 would make a direct approach as though intending to overfly the Soviet fortification. The mission would be flown late at night, when the least experienced personnel would be manning the missile site. The SR-71 night time flight performance restrictions were lifted so the flight could be flown at max Mach (3.2) and turns made at max bank of 35 degrees instead of the normal 25-degrees.
The exigencies of the mission were: (1) to fly the SR-71 faster at night than it had previously been flown; (2) to fly well within effective range of the Soviet Union’s most capable surface-to-air missile system without the SR-71 having either a missile warning or defense system available; and (3) to use a steeper bank angle than any prior night flights. Both the speed and bank angle had never been attempt before by anyone at night.
The potential results of the mission were so crucial to our wartime retaliatory capability that the order to execute the flight was initiated at the highest level of the National command authority (the President).
It followed that the most senior and experienced crewmembers would be selected to fly the mission, and that was the crew of Colonels Spencer and Sheffield. During the mission both the skill and experience of the crew were relied on heavily for its successful completion.
Photo credit: Unknown via Habubrats and George Chernilevsky via Wikipedia
It’s more of a question than a comment. Why didthe sr-71 have restrictions on night time flying? I understand that it’s easier to see during the day than night but that’s about it. Can someone plz explain the difference between banking at 25 & 35 degrees so I can understand this please?